ch 7 pt 2

-extends from skull to pelvis

-also called spine or spinal column

-function: transmit weight of trunk to lower limbs, surround and protect spinal cord, provide attachment for ribs and muscles

-contains 26 irregular bones (vertebrae)

-28" long

1. cervical - contains 7 vertebrae

2. thoracic- 12 vertebrae

3. lumbar- 5 vertebrae

4. sacrum

5. coccyx (tail bone)

1. cervical and lumbar-concave posteriorly

2. thoracic and sacral curvatures-convex posteriorly

along with trunk muscles, help support vertebral column

-anterior and posterior longitudinal ligaments: continuous bands from neck to sacrum that run down front and back of spine

-ligament flavum: connects adjacent vertebrae

-short ligaments: connect ea. vertebra to those above and below

-cushionlike pad sand wiched between vertebrae that act as shock absorbers

-composed of two parts:

1.nucleus pulposus-inner gelatinous nucleus, gives disc elasticity and compressibility

1. anulus fibrosus- outer collar composed of collagen and fibrocartilage, limits expansion when compressed

abnormal lateral rotation of spine, most often in thoracic region, which may lead to breathing difficulties

abnormal dorsal thoracic curvature common in people with osteoporosis, tuberculosis of spine, rickets, or osteamalacia

accentuated lumbar curvature that can result from disease but is also seen in men with pot bellies and in pregnant women

-body (centrum)

-vertebral arch: two pedicles, two laminae

-vertebral foramen

-vertebral canal

-intervertebral foramina

1. spinous process: projects posteriorly

2. transverse processes (2): project laterally

3. superior articular processes (2): protrude superiorly

4. inferior articular processes (2): protrude inferiorly

cervical (3-7): small, oval wide side to side

thoracic: larger than cervical; heart shaped; bears two costal facets

lumbar: massive; kidney shaped

cervical (3-7): short, bifid (except); projects directly posterior

thoracic: long; sharp; projects inferiorly

lumbar: short, blunt; rectangular; projects directs posteriorly

cervical (3-7): triangular, large

thoracic: circular

lumbar: triangular

cervical (3-7): contain foramina

thoracic: bear facets for ribs

lumbar: thin and tapered

cervical (3-7): superior facets directed superoposteriorly, inferior facets directed inferoanteriorly

thoracic: superior facets directed posteriorly, inferior facets directed anteriorly

lumbar: superior facets directed posteromedially, inferior facets directed anterolaterally

cervical (3-7): flexion and extension; lateral flexion; rotation; the spine region

thoracic: rotation; lateral flexion possible but restricted by ribs; flexion and extension limited

lumbar: flexion and extension; some lateral flexion; rotation prevented

-superior articular process and facet

-inferior articular process

-spinous process

-body

-transverse foramen

-transverse process

-vertebral foramen

-spinous process

-vertebral foramen

-transverse costal facet (for tubercle of rib)

-superior costal facet (for head of rib)

-body

-transverse process

-superior articular process and facet

-body

-spinous process

-vertebral foramen

-transverse process

-superior articular process

-c1 to c7: smallest, lightest vertebrae

-c3 to c7: share features

>> oval shaped body (c7 spinous processes are split), large, triangular foramen, transverse foramen, c7 is vertebra prominens

-c1: atlas

-c2: axis

found in each transverse process for artery passageways

large and can be felt through skin, used as a landmark

-C1

-no body or spinous process

-consists of anterior and posterior arches, and two lateral masses

-superior surfaces of lateral masses articulate with occipital condyles

-movement for nodding the head "yes"

-C2

-has body and processes like other vertebrae

-major feature is knoblike dens that projects superiorly into anterior arch of atlas

-dens is a pivot for rotation of atlas

-movement allows side to side rotation for saying "No"

-T1 to T12 increase in size and articulate with ribs

-body is heart shaped with two small demifacets that articulate with ribs

-T10-T12 only have a single facet

-vertebral foramen is circular

-long, sharp spinous process, points inferiorly

-transverse processes have transverse costal facets

-L1 toL5

-"small of back"; recieves most stress

-short, thick pedicles and laminae

-flat, hatchet-shaped spinous processes point posteriorly

-vertebral foramen is triangular

-orientation of articular facets locks lumbar vertebrae together to prevent rotation

triangular bone shapes posterior wall of pelvis; made from 5 fused vertebrae (S1-S5)

-superior articular process (articulates with L5)

-articulates inferiorly with coccyx and laterally with hip bones via its articular surfaces, forming sacroiliac joints

-sacral promontory

-transverse ridges (mark lines of fusion)

-anterior sacral foramina (lie at lateral ends of ridges; act as openings for nerves and vessels

-alae: winglike expansions

-median sacral crest: roughened bumps on posterior midline

-lateral sacral crest: roughened ar5ea seen laterally on posterior side

-posterior sacral foramina: large openings for sacral spinal nerves

-sacral canal: continuation of vertebral canl

-sacral hiatus: large opening at end of canal

tailbone formed from three to five fused vertebrae; articulates superiorly with sacrum

-very little function

composed of: thoracic vertebrae, sternum, costal cartilage, ribs

-functions: protects vital organs of thoracic cavity, supports shoulder girdles and upper limbs, provides attachment sites for muscles of neck, back, chest, and shoulders

-called the breastbone, consists of three fused bones

-manubrium: superior portion articulates with clavicular notches and ribs 1 and 2

-body: midportion that articulates with costal cartilages of ribs 2-7

-xiphoid process: inferior end that is site of muscle attachment

1. jugular notch: central indentation in superior border of manubrium

2. sternal angle: horizontal ridge across front of sternum

3. xiphisternal joint: point where sternal body and xiphoid process fuse

-12 pairs

-all attach posteriorly to bodies and transverse processes of thoracic vertebrae

-true ribs: pairs 1-7 attach directly to the sternum

-false ribs: 8-10 attach indirectly to sternum by joining costal cartilage

-floating ribs: 11-12 no attachment to sternum

-shaft: flat bone that makes up most of the rib

-costal groove: houses nerves and vessels

-head: posterior end articulates with facets

-neck: contricted portion beyond head

-tubercle: knoblike structure lateral to neck

1. pectoral girdle: attaches upper limbs to body trunk

2. pelvic girdle: attaches lower limbs to body trunk

-shoulder girdle

-consists of clavicles and scapulae

-attach upper limbs to axial skeleton

-provide attachment sites for muscle

-called collarbones

-S-shaped sternal end articulates with sternum medially

-Flattened acromial end articulates laterally with scapula

-anchor muscles and act as braces to hold the scapulae and arms out laterally

-called the shoulder blades, thin, flat bones, between ribs 2 and 7

-has 3 borders: 1. superior (shortest, sharpest) 2. medial (runs parallel to spine) 3. lateral (near armpit ends superiorly in glenoid cavity)